# study_deck_02

An Anki-exportable study deck for NeetCode DSA problems.

## How It Works

1. **Roadmap** (`roadmap.org`) — the tracker. Lists all NeetCode 150 topics
   and problems. Toggle `TODO` → `DONE` with `g c c` in Emacs as you
   complete each one. Progress cookies (`[/]`) show topic completion.

2. **Notes** (`dsa/<topic>/<problem>.org`) — the real work. Each problem
   has its own file with:
   - Approach notes (write your own)
   - Python and C++ solution stubs
   - A `NEETCODE` property linking back to the roadmap

3. **Toolkit** (`toolkit/`) — your reference library:
   - `tricks.org` — flashcards for patterns & tricks (exported to Anki)
   - `notes.org` — deep implementation notes with explanations (exported to Anki)
   - `suggestions.org` — pattern reference for quick lookup (not exported)

4. **Study flow** — open roadmap.org, pick a topic, pick a problem,
   follow the Notes link, solve it, mark it DONE in both places.

## File Layout

```
org/study_deck_02/
├── AGENTS.md                ← you are here
├── roadmap.org              ← generated by leetcode/extract.mjs
├── toolkit/
│   ├── tricks.org           ← flashcards for patterns & tricks
│   ├── notes.org            ← deep implementation notes
│   ├── suggestions.org      ← pattern reference (not exported)
│   └── images/              ← diagrams, screenshots
└── dsa/
    ├── arrays-hashing/
    │   ├── 0217-contains-duplicate.org
    │   └── ...
    ├── two-pointers/
    ├── sliding-window/
    ├── linked-list/
    ├── binary-search/
    ├── stack/
    ├── trees/
    ├── tries/
    ├── heap-priority-queue/
    ├── backtracking/
    ├── graphs/
    ├── advanced-graphs/
    ├── 1-d-dynamic-programming/
    ├── 2-d-dynamic-programming/
    ├── greedy/
    ├── intervals/
    ├── math-geometry/
    └── bit-manipulation/
```

18 topics, 199 problems (NeetCode 150).

## The `#+ANKI_DECK: study_deck_02` Header

Every `.org` file in this deck has `#+ANKI_DECK: study_deck_02` at the
top. This tells org-anki which Anki deck to export into. Without it,
the file won't be picked up by the exporter.

To override per-card, use `:ANKI_DECK:` in the properties drawer.

## Roadmap Format

Each problem in roadmap.org uses a properties drawer to keep links tidy:

```org
** TODO 0217. Contains Duplicate :easy:
:PROPERTIES:
:LEETCODE: [[https://leetcode.com/problems/contains-duplicate/][Problem]]
:CPP:      [[https://github.com/neetcode-gh/leetcode/blob/main/cpp/0217-contains-duplicate.cpp][Solution]]
:PYTHON:   [[https://github.com/neetcode-gh/leetcode/blob/main/python/0217-contains-duplicate.py][Solution]]
:VIDEO:    [[https://youtube.com/watch?v=3OamzN90kPg][Watch]]
:END:
Notes: [[dsa/arrays-hashing/0217-contains-duplicate.org][My Solution]]
```

Properties are hidden by default in Emacs (`TAB` to cycle). The Notes
link is always visible — that's the one you click most.

## Notes Format

Each problem note links back to the roadmap via the `NEETCODE` property:

```org
* TODO 0217. Contains Duplicate :easy:
#+ANKI_DECK: study_deck_02
:PROPERTIES:
:NEETCODE: [[../../roadmap.org::*0217. Contains Duplicate][Roadmap]]
:END:

** TODO Approach
Write your approach here.

** TODO Python
#+begin_src python

#+end_src

** TODO C++
#+begin_src cpp

#+end_src
```

## Regenerating

From the `leetcode/` directory:

```bash
node extract.mjs              # fetches fresh data, writes roadmap.org here
node scaffold-notes.mjs       # creates missing note files (skips existing)
```

Extract pulls from neetcode.io (cached in `leetcode/.cache/`). Scaffold
is idempotent — it only creates files that don't exist yet.

## Growing the Deck

This deck starts with NeetCode 150. To add more:

- **More problems** — edit `extract.mjs` to include `neetcode250` or
  `blind75` flags, or remove the `neetcode150` filter entirely.
- **Custom topics** — add new folders under `dsa/`, create notes manually.
- **Other sources** — create new folders alongside `dsa/` (e.g.,
  `euler/`, `advent-of-code/`) with the same `#+PROPERTY: STUDY_DECK_02`
  header. They'll all export to the same Anki deck.
- **Flashcards** — add `** Front` / `** Back` sections to any note
  for Anki-style cards (see root `AGENTS.md` for format).

## Backlinking Convention

Every `.org` file should link back to `roadmap.org` via a property:

- Problem notes use `:NEETCODE:` linking to the roadmap heading
- Toolkit/tricks use `:ROADMAP:` linking to a relevant problem
- Roadmap entries use `:TRICK:` linking to relevant tricks

This keeps the web of links navigable in both directions — from
roadmap to notes, from notes to tricks, and tricks back to problems.